Java Reference
In-Depth Information
65
// construct a new PrimeCalculator object
calculator =
new
PrimeCalculator(number,
displayPrimesJTextArea, statusJLabel, getPrimesJButton,
cancelJButton);
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// listen for progress bar property changes
calculator.addPropertyChangeListener(
new
PropertyChangeListener()
{
public void
propertyChange(PropertyChangeEvent e)
{
// if the changed property is progress,
// update the progress bar
if
(e.getPropertyName().equals(
"progress"
))
{
int
newValue = (Integer) e.getNewValue();
progressJProgressBar.setValue(newValue);
}
}
}
// end anonymous inner class
);
// end call to addPropertyChangeListener
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// disable Get Primes button and enable Cancel button
88
getPrimesJButton.setEnabled(
false
);
89
cancelJButton.setEnabled(
true
);
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calculator.execute();
// execute the PrimeCalculator object
92
}
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}
// end anonymous inner class
94
);
// end call to addActionListener
95
northJPanel.add(getPrimesJButton);
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// add a scrollable JList to display results of calculation
98
displayPrimesJTextArea.setEditable(
false
);
99
add(
new
JScrollPane(displayPrimesJTextArea,
100
ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS
,
101
ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER
));
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// initialize a panel to display cancelJButton,
104
// progressJProgressBar, and statusJLabel
105
JPanel southJPanel =
new
JPanel(
new
GridLayout(
1
,
3
,
10
,
10
));
106
cancelJButton.setEnabled(
false
);
107
cancelJButton.addActionListener(
108
new
ActionListener()
109
{
110
public void
actionPerformed(ActionEvent e)
111
{
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}
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}
// end anonymous inner class
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);
// end call to addActionListener
calculator.cancel(
true
);
// cancel the calculation
Fig. 23.27
|
Using a
SwingWorker
to display prime numbers and update a
JProgressBar
while the prime numbers are being calculated. (Part 3 of 4.)
